Seeing touch and haptic events entrains the brain activity

Researchers measured brain activity in volunteers who were given tactile stimuli while watching a movie.

Researchers at Aalto University and the University of Helsinki have studied how somatosensory brain activity changes while the subjects watch a movie. The researchers were particularly interested in how the viewers’ brain activity varies during scenes that displayed haptic events, that is, interaction involving touch. In such scenes, the main character was e.g. sliding down a rocky cliff or manipulating stones on the shore.

“16 healthy men and women, between the ages of 20 and 60, participated in the study. After the measurements, the subjects watched the film once again and assessed numerically how haptically immersed they felt to be in different parts of the movie”, explains doctoral candidate Kaisu Lankinen from the Department of Neuroscience and Biomedical Engineering.

Brain activation changed concordantly with the contents of the movie. For example, during scenes involving haptic events, cortical activity was different from that during scenes involving scenery.

Brain activity of the volunteers was recorded with magnetoencephalography (MEG), which measures magnetic fields induced by the brain’s minute neural currents.

“To probe brain areas related to haptic processing, tactile stimuli were delivered to the subjects' fingers while they were watching the movie. We developed a novel means to analyse time-varying changes in the resulting brain responses”, Lankinen continues.

“By using movies in brain research, we can build naturalistic, real-world-like experimental settings and study brain processes supporting social interaction and perception of complex social events. MEG allows to examine very fast phenomena in the brain, as its time resolution is of the order of milliseconds.”

The study is a part of Kaisu Lankinen's doctoral dissertation with the purpose to develop new analysis methods and approaches for using MEG to study sensory and cognitive brain processing in naturalistic experimental settings, such as during movie viewing.